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adjacent
angles  two angles that share a vertex and a common
side between them but have no interior points in common.
algorithm
 a stepbystep procedure for carrying out computation.
alternate
angles  two angles that are in opposite locations
when lines are cut by a transversal. If the angles are between
the lines, they are called alternate interior angles; if they
are outside the lines, they are called alternate exterior
angles. If the lines are parallel, the alternate angles are
congruent.
area
 The extent of a planar region or of the surface of a solid
measured in square units.

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bias
 A statistical sampling or testing error caused by systematically
favoring some outcomes over others.
bisector
of an angle  a segment or ray that divides an angle
into two congruent angles.
bisector
of a line segment  a point, segment, ray, or line
that divides a line segment into two congruent segments.
boxandwhiskers
plot  a type of graph used in data management particularly
useful in showing the spread of the distribution of the data.
brokenline
graph  a type of graph used in data management where
the data points are joined by line segments. Also called simply
a line graph. 
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capacity
 The maximum amount a container holds, usually measured in
litres.


census
 When information is gathered from all people in the population,
the activity is called a census. Polls or surveys are a method
of collecting data by asking people to give their answers
to a set of questions.
chord
 a segment joining two points on a circle.
circle
graph  a graph of statistical data where a circle
is subdivided into regions that represent the percent of the
total.
complementary
angles  two angles whose measures total 90 degrees.

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circumference
 The distance around (perimeter of) a circle.
compound
event  the outcome of a probability experiment that
involves more than one object. E.g.: when you roll two dice
and the result is a 5 on one and a 2 on the other, this is
a compound event.
congruent
 figures that have the same size and same shape.
congruent
angles  angles that have the same measure.
congruent polygons  plane figures that are
the same size and shape.
corresponding
angles  angles that have the same relative positions.
In parallel lines corresponding angles are congruent. 



data
 Facts and opinions from which conclusions can be drawn.
dependent
events  when determining probability those events
whose outcomes affect each other.


diameter
 A chord that passes through the centre of a circle.


displacement
 When an object is dropped into fluid, the fluid is
displaced (moved) to make room for the space that the other
object requires. 



edge
 the line segment where two faces of a polyhedron
meet
equiangular
or equilateral triangle  see regular polygon.
estimation
 determining an approximate amount, value, or size of something.
Quantitative estimation is determining the approximate
number of items in a group. Computational estimation
is determining the approximate result to an arithmetic calculation.
Measurement estimation is determining the approximate length,
perimeter, area, volume, or other measurement of a geometric
figure.
Euler's
formula  a formula relating the number of vertices
(V), faces (F) and edges (E) of a polyhedron. V + F  E
= 2
event
 one or more outcomes of a probability experiment.
experimental
probability  the ratio of the favorable outcomes
to the total outcomes in an experiment. e.g.. the experimental
probability of drawing a 10 of spades from a deck of cards
is 1:2.

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face
 any of the flat sides of a polyhedron
frequency
diagram  used in statistics as a method of recording
the data collected. A tally is often used in the
frequency diagram to keep track of the number of times something
occurs.

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histogram
 a type of statistical graph that uses bars, where each bar
represents a range of values and the data are continuous.




isosceles
 a polygon with two sides equal in length. Usually used to
refer to either a triangle or a trapezoid. 

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length
The measurement of the extent of something along its greatest
dimension: the length of the boat.
line
graph  see broken line graph
line
of symmetry  a line that divides a figure into two
parts, each a mirror image of the other.




mass
 The measurement of the amount of matter in an item.
mean
 in statistics, the measure of central tendency calculated
by adding all the values and dividing the sum by the number
of values. (Often referred to as the average.)
median
statistical
 the measure of central tendency that is in the middle when
the values are arranged in order of size. If there is an even
number of data items, the median is the mean of the middle
two.
of a triangle
 a line segment from any vertex of a triangle to the midpoint
of the opposite side.
mode
 the value that appears most frequently in a set of data.




net
 a plane figure obtained by opening and flattening a 3D object,
or a 2D pattern for a 3D object. 



observation
 The act of noting and recording something, such as a phenomenon,
with instruments.
obtuse
triangle  a triangle with one obtuse angle.
odds
 the probability that an event will occur compared with the
probability of its not occurring.




parallelogram
 A quadrilateral with opposite sides parallel.
perimeter
 The distance around an object.
pi
(3.14)  The ratio of the circumference to the diameter (C/d)
of any circle.
polygon
 a closed figure made up of line segments.
polyhedron
 a 3D object that has polygons as its faces. The intersection
of any two faces forms an edge.
population
 Refers to the entire group about which data are being collected.
prism
 a geometric solid with two bases that are congruent, parallel
polygons, and all other faces are parallelograms. It is referred
to as a right prism if the faces are rectangles. It is named
according to the shape of its bases; e.g.: triangular prism.
protractor
 a half circular device subdivided into 360 equal parts and
used for measuring angles.
pyramid
 a geometric solid with one base that is a polygon and all
other faces are triangles with a common vertex.
Pythagorean
Theorem in any right triangle, the square
of the length of the hypotenuse equals the sum of the squares
of the other 2 sides.




questionnaire
 A form containing a set of questions, especially one addressed
to a statistically significant number of subjects as a way of
gathering information for a survey.




radius
 The distance from the centre of a circle to any point on
the circle.
random
sample  Is a sample drawn in such a way that every
member of the population has an equal chance of being chosen.
Random sampling is often used in taking surveys when it is
not feasible to survey every possible person.
range
 in statistics, the difference between the least and the
greatest values in a set of data. In more advanced statistics,
it is considered the number of values between the greatest
and the least, inclusive, and is calculated by the formula:
range = greatest  least + 1.
reflection
(flip)  a transformation of a geometric figure that results
in a mirror image of it. The object and the image are equal
distance from the line of reflection.
reflex
angle  an angle whose measure is between 180 degrees
and 360 degrees
research
 Scholarly or scientific investigation or inquiry.
rhombus
 a parallelogram with all sides equal in length
rotation
(turn)  a transformation of a figure in which the image is
formed by turning the figure about a fixed point called the
centre of rotation. The centre may be inside or outside the
figure.




sample
 A set of elements drawn from and analyzed to estimate the
characteristics of a population. Also called sampling.
sample
size  The number of items in a sample.
scale
factor  The ratio of a distance measured on a scale
drawing to the corresponding distance measured on the actual
object.
scalene
triangle  a triangle with all sides of different
lengths.
secant
of a circle  a line that intersects a circle in
two points
similar
polygons  polygons that have the same shape but
not necessarily the same size.
simplest
form  fraction is in simplest form if both its numerator
and denominator are whole numbers and their only common factor
is 1.
stem
and leaf plot 
in statistics, a way of recording, organizing and displaying
numerical data so that the original data remains intact.
supplementary
angles  two angles whose measures total 180 degrees.
surface
area  The sum of the areas of all the faces, including
the bases, of a 3D object.

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tessellate
 the repeated use of geometric figures to completely fill a
plane without gaps or overlapping. theoretical
probability  probability that is determined on the
basis of reasoning, not through experimentation. E.g.: because
a regular die has 6 sides, the theoretical probability of
tossing a 3 is 1/6.
translation
(slide)  an exact duplication of a geometric figure formed
by moving each point in the figure the same distance and in
the same direction.
transversal
 a line that intersects two or more lines in the same plane
trapezoid
 a quadrilateral with exactly one pair of parallel lines.






vertex
(plural: vertices)  the point of intersection of two rays
that form an angle, two sides of a polygon, or two edges of
a solid.
vertically
opposite angles  two angles formed by the intersection
of two lines. They share a common vertex but no sides or interior
points.
volume
The amount of space occupied by a threedimensional object
or region of space, expressed in cubic units. Or, The capacity
of such a region or of a specified container, expressed in
cubic units. 



weight
 The measurement of how heavy an item is; The force with which
a body is attracted to Earth or another celestial body, equal
to the product of the object's mass and the acceleration of
gravity.


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